Compared peer relations, developmental expectations, perceived competence, and well-being in Dutch and Japanese adolescents, investigating cultural influences. Survey data indicated that Dutch adolescents were more satisfied with their peer relationships, expected to achieve developmental tasks at earlier ages, felt more competent about their abilities, and reported higher levels of well-being than did Japanese adolescents. Peer relations had stronger associations with developmental expectations and well-being among Japanese adolescents. (Contains references.) (SM)